public static QueryableClosure AddIsNullClosure(
this IQueryableFilterVisitorContext context,
Type type)
{
QueryableClosure closure =
context.AddClosure(type, "_s" + context.Closures.Count, false);
context.GetLevel().Enqueue(FilterExpressionBuilder.Equals(closure.Parameter, null));
return(closure);
}
public static QueryableClosure AddClosure(
this IQueryableFilterVisitorContext context,
Type type,
string parameterName,
bool inMemory)
{
var closure = new QueryableClosure(type, parameterName, inMemory);
context.Closures.Push(closure);
return(closure);
}
public static bool TryCreateLambda(
this QueryableClosure closure,
[NotNullWhen(true)] out LambdaExpression?expression)
{
expression = null;
if (closure.Level.Peek().Count == 0)
{
return(false);
}
expression = closure.InMemory ?
Expression.Lambda(closure.GetExpressionBodyWithNullCheck(), closure.Parameter) :
Expression.Lambda(closure.Level.Peek().Peek(), closure.Parameter);
return(true);
}
public QueryableFilterVisitorContext(
IReadOnlyList <IExpressionOperationHandler> operationHandlers,
IReadOnlyList <IExpressionFieldHandler> fieldHandlers,
ITypeConversion typeConverter,
QueryableClosure closures,
bool inMemory)
{
if (closures is null)
{
throw new ArgumentNullException(nameof(closures));
}
OperationHandlers = operationHandlers ??
throw new ArgumentNullException(nameof(operationHandlers));
FieldHandlers = fieldHandlers ??
throw new ArgumentNullException(nameof(fieldHandlers));
TypeConverter = typeConverter ??
throw new ArgumentNullException(nameof(typeConverter));
InMemory = inMemory;
Closures = new Stack <QueryableClosure>();
Closures.Push(closures);
}
private static Expression GetExpressionBodyWithNullCheck(this QueryableClosure closure) => FilterExpressionBuilder.NotNullAndAlso(closure.Parameter, closure.Level.Peek().Peek());
